The present invention relates to a reference voltage generation circuit, a display drive circuit, a display device and a reference voltage generation method.
Small-sized formation and highly fine formation are required in a display device represented by an electro-optical device of a liquid crystal device and the like. Among them, a liquid crystal device realizes low power consumption and is frequently mounted on a portable electronic device. For example, when a liquid crystal device is mounted as a display portion of a portable telephone, there is requested display of image rich in color tone by many gray scales formation.
Generally, an image signal for displaying an image is subjected to gamma correction in accordance with a display characteristic of a display device. The gamma correction is carried out by a gamma correction circuit (in wide sense, reference voltage generation circuit). Taking an example of a liquid crystal device, a gamma correction circuit generates voltage in accordance with transmittance of a pixel based on gray scale data for carrying out gray scale display.
Such a gamma correction circuit can be constituted by a ladder resistor. In this case, voltages across two opposed ends of respective resistor circuits constituting the ladder resistor are outputted as multi-valued reference voltages in accordance with gray scale value.